The college basketball postseason, at least as far as the ACC is concerned, doesn’t officially begin until next Thursday in Greensboro. The real madness of March, however, gets underway Saturday night in Chapel Hill when North Carolina and Duke square off in their traditional season-ending showdown.

All the usual trappings of the occasion will be on display, including a cameo appearance by ESPN’s College GameDay crew. The only thing that will be missing are the high stakes that are usually involved when the Blue Devils and Tar Heels lock horns at this time of year.

While Duke can still steal a share of the league title with a win and a little help from Miami, and UNC’s final seeding still hinges on the outcome, the 236th meeting between the neighboring rivals will be more about bragging rights and serving “as a springboard for the ACC tournament” – as Blue Devils coach Mike Krzyzewski said – than anything tangible.

It also offers an intriguing contrast between evolving teams that are each very different from the first time they met just 3˝ weeks ago.

Duke won that game 73-68, battling from behind on the strength of an 18-point, 11-rebound performance by senior center Mason Plumlee. But even in defeat, it was the Tar Heels that gained the most from the emotional night at Cameron Indoor Stadium because of the lineup change that has served as the turning point of their season.

UNC (22-8, 12-5 ACC) hasn’t lost since coach Roy Williams finally gave in and installed sophomore P.J. Hairston as a starter in a smaller, quicker four-guard alignment.

Not only has the addition of Hairston given the Tar Heels a third viable scoring option in addition to Reggie Bullock and James Michael McAdoo, the only true big man left on the floor, the extra spacing his presence creates has helped bring out the best in senior Dexter Strickland and freshman point guard Marcus Paige.

“In the preseason I said I thought my team would get better and better as the season went along and I really think they have,” Williams said. “The small lineup gives too much credit to coaching. The kids have really bought into the sense of urgency, the unselfishness, the gang rebounding, and the total play on the offensive and defensive end of the floor. They should feel very good about what they’ve done.”

The obvious downside to the new downsized strategy is the vulnerability it creates both defensively and on the boards against top teams with a strong low post presence.

Duke (26-4, 13-4) happens to be one of those teams, especially now that Ryan Kelly is back in the lineup after missing two months with a foot injury.

The 6-foot-10 forward has already showed his value to the Blue Devils by pumping in 36 points on 7-of-9 shooting from 3-point range in a triumphant return performance against Miami last week, then following that up with an 18-point, nine-rebound, five-assist effort in Tuesday’s Senior Night win against Virginia Tech.

Page 2 of 2 - Kelly’s length and versatility are likely to create a difficult matchup for Tar Heels, who must decide whether to double on Plumlee inside, as they did in the first meeting, or use that second defender to shadow Kelly everywhere he goes.

Even if it chooses the latter, the 6-5˝ Hairston figures to have his hands full.

Because unlike N.C. State’s C.J. Leslie, whose size advantage was effectively negated by Hairston’s bulk and strength, Kelly has a variety of different ways to put the ball in the basket – along with the patience and poise to use them.

He can post Hairston up. He can put the ball on the floor and attack the rim. And, as he shown throughout his career, he simply can step outside to the perimeter and get 3-point shots off over his smaller defender.

Kelly’s presence could end up forcing Williams into amending his strategy and playing a bigger lineup for longer than he’d like. Then again, UNC’s new faster-paced approach and the improved play of Paige at the point could just as easily force Krzyzewski into the adjustments.

It’s a chess match that promises to make this latest rivalry matchup as captivating as always, even without the usual high stakes.